This invention relates to the field of chemical engineering, and particularly to apparatus for deriving potable water from a source which because of non-volatile pollutants is saline or otherwise not potable, although the invention is usable in other chemical applications as well.
There are many undeveloped areas of the world where potable water is scarce and expensive, although brackish water is plentiful and accessible at different temperatures, and where the supplies of electrical or mechanical energy common to more developed areas are simply not available.
The ocean is available as a source of relatively cool water, being maintained at a temperature about 25.degree. C. even in the tropics. It is also well known that water at temperatures of 55.degree. C. and even higher can readily be obtained from sources known as "solar ponds": such a pond may comprise an enclosed body of water, located to receive radiant energy from the sun, and covered with material which is transparent to solar energy but is impervious to water vapor, to prevent the loss of heat which accompanies evaporation.
My apparatus operates to provide a continual source of potable water under these conditions, being maintained in operation solely by the stored energy represented by the difference in temperature between the two sources of water.